This application claims the priority of German application 196 44 531.0-21 filed in Germany on Oct. 26, 1996, the disclosure of which is expressly incorporated by reference herein.
The invention relates to an automobile with a body support structure having a front area and a rear area, as well as with a body cladding connected with the body support structure, with the body support structure having in the front area a set area to receive a drive assembly as well as associated functional units.
In automobiles, it is known (VDI-Berichte 968 "Entwicklungen im Karosseriebau" Developments in Body Construction!, VDI-Verlag, Dusseldorf, 1992) to make the self-supporting body not exclusively of steel but of a mixed construction. In this mixed construction, the body support structure is made of sheet steel and the body cladding is made of aluminum sheet. This results in a weight reduction for the automobile that produces an improvement in driving dynamics as well as a reduction of fuel consumption. Mixed construction however can lead to unfavorable axle load distribution which must be compensated by additional design measures.
A goal of the invention is to produce an automobile of the species recited at the outset that has a weight that has been reduced relative to known sheet steel designs and nevertheless has a favorable axle load distribution.
This goal is achieved by virtue of the fact that a portion of the body support structure associated with the front area, especially the set area, or the rear area, as well as the body parts of the body cladding surrounding this section asymmetrically with respect to the center of gravity of the vehicle are made at least partially of a material with reduced weight relative to the rest of the body support structure and relative to the rest of the body cladding. The solution according to the invention takes its departure from the fact that the lightweight measures pertain only to the self-supporting body and not to the drive assembly itself. With a symmetrical arrangement of the lightweight elements over the length of the body, because of the still-high weight of the drive assembly at the wheel axis adjacent to the drive assembly, a high axle load would result that would lead to poor driving dynamics, especially to poor traction.
A different distribution of the axle load such as shifting the battery to the vicinity of the other wheel axis would result in a certain degree of compensation but at the same time it would reduce the useful space inside the vehicle body. Firstly, the battery would require additional space for installation in the vicinity of the other wheel axis and secondly the remote location of the battery from the associated functional units would require longer cable and connector pathways that would also take up additional space.
The solution according to the invention takes a completely different approach that does not provide symmetrical but rather asymmetrical distribution of the lightweight structural elements, especially in the body area that has a high weight because of the drive assembly. Since conventional sheet steel construction is retained in the remaining areas of the body, balanced and optimized axle load distribution is achieved even without additional axle load distribution measures. In the vicinity of the wheel axis where the heavy drive assembly is located, the body is made with a lightweight design while the conventional design is retained in the vicinity of the other wheel axis. As a result, weight reduction is obtained that is not as great as with symmetrical mixed construction, but this disadvantage is more than compensated by the automatically favorable axle load distribution as well as the fact that the installation space required does not have to be reduced and also by the reduction in costs due to lower expenditure.
The solution according to preferred embodiments of the invention described above applies in particular to an automobile with a front mounted engine and a rear wheel drive. The solution according to the invention can also be advantageously used for automobiles with rear engines or for automobiles with a front mounted engine and front wheel drive according to other contemplated preferred embodiments. In an automobile with a front mounted engine and front wheel drive, locating the weight-reducing parts in the rear improves the traction of the vehicle.
In the design of the invention, the area of the body structure associated with the set area as well as the body parts surrounding this area are made of a lightweight material, especially aluminum, and the remaining body support structure and body cladding are made of steel. The use of aluminum is especially beneficial in view of the advantageous ways in which the material can be worked.
In another embodiment of the invention, chassis parts, especially a wheel axle, are made of lightweight material in the vicinity of the set area. This creates another possibility for saving weight in the set area. This design is advantageous if the measures already described for weight reduction of the body in the vicinity of the set area are insufficient for uniform axle load distribution on the front and rear axles.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.